1. Field of the Invention
The invention relates to nickel electroforms.
2. Description of Prior Art
Nickel electrodeposition processes are well-known and pulse currents with rectangular waveforms, instead of direct current, are commonly used to enhance deposition quality. The quality and repeatability of surface finishes provided by this process, especially to meet the requirements of modern micro-device products, has generated many proposals that are generally focussed on using different rectangular waveforms. It has however been proposed to use other types of waveforms in a Paper published in Surface Coatings and Technology 115 (1999) 132-139 entitled xe2x80x98A study of surface finishing in pulse current electroforming of nickel by utilising different shaped waveformsxe2x80x99. However, repeatable extremely high quality surface finishes have not yet been attained.
It is an object of the invention to overcome or at least reduce this problem.
According to the invention there is provided a nickel electrodisposition process for creating electroforms having extremely high quality surface finishes, the process comprising applying pulses of direct current in which each pulse has a waveform with a ramp-down spike.
Each waveform may have a ramp-down spike in a rectangular waveform, in a triangular waveform, or, preferably, in a ramp down waveform.